A project widening Interstate 12 from four to six lanes in the Slidell area has been completed after more than a year of construction, state officials announced Friday. The $25.7 million project stretches from the interchange with Interstate 10, Interstate 12 and Interstate 59 to west of Vincent's Bayou Bridge. It's an area used by 70,000 drivers daily.

From the Robert Road overpass, widening of Interstate 12 in the Slidell area from the I-10/I-12/I-59 interchange to just west of the Vincent's Bayou Bridge is shown in March.David Grunfeld / The Times-Picayune

When construction began in March 2011, Gov. Bobby Jindal said the I-12 corridor is critical for the entire state. He said the project would ensure safer commutes and enhancing economic opportunities.

"Not only is that where you see a high volume of traffic as people go back and forth to work, but it's also a major freight corridor for Louisiana as far as being able to efficiently transport goods and services for trucking industries," said Amber Leach, a spokeswoman for the state Department of Transportation and Development.

Leach said the project was paid for entirely with surplus funds from 2008. Over the past four years, she said, the Department of Transportation has invested $257 million in improvements to I-12 statewide.

On Monday, state Transportation Secretary Sherri LaBas will join with other state and local leaders for a ribbon-cutting ceremony in Slidell.

The project also widened the I-12 eastbound off-ramp to Northshore Boulevard from one to two lanes and added a slow-down lane at the I-12 westbound off-ramp to Airport Road.